外文翻譯--可編程邏輯控制器及其控制系統(tǒng)

1、中文 中文 5000 字本科 本科畢業(yè)設(shè)計 畢業(yè)設(shè)計外文翻 外文翻譯外文 外文譯文題目（中文） 目（中文）可編程邏輯 邏輯控制器及其控制系 控制器及其控制系統(tǒng) 2 Programmable logic controllers I/O channel specifications include total number of points, number of inputs and outputs, ability to expand

2、, and maximum number of channels. Number of points is the sum of the inputs and the outputs. PLCs may be specified by any possible combination of these values. Expandable units may be stacked or linked together to incr

3、ease total control capacity. Maximum number of channels refers to the maximum total number of input and output channels in an expanded system. PLC system specifications to consider include scan time, number of instruct

4、ions, data memory, and program memory. Scan time is the time required by the PLC to check the states of its inputs and outputs. Instructions are standard operations (such as math functions) available to PLC software.

5、Data memory is the capacity for data storage. Program memory is the capacity for control software.Available inputs for programmable logic controllers include DC, AC, analog, thermocouple, RTD, frequency or pulse, transi

6、stor, and interrupt inputs. Outputs for PLCs include DC, AC, relay, analog, frequency or pulse, transistor, and triac. Programming options for PLCs include front panel, hand held, and computer.Programmable logic contro

7、llers use a variety of software programming languages for control. These include IEC 61131-3, sequential function chart (SFC), function block diagram (FBD), ladder diagram (LD), structured text (ST), instruction list (I

8、L), relay ladder logic (RLL), flow chart, C, and Basic. The IEC 61131-3 programming environment provides support for five languages specified by the global standard: Sequential Function Chart, Function Block Diagram, La

9、dder Diagram, Structured Text, and Instruction List. This allows for multi-vendor compatibility and multi-language programming. SFC is a graphical language that provides coordination of program sequences, supporting alt

10、ernative sequence selections and parallel sequences. FBD uses a broad function library to build complex procedures in a graphical format. Standard math and logic functions may be coordinated with customizable communicat

11、ion and interface functions. LD is a graphic language for discrete control and interlocking logic. It is completely compatible with FBD for discrete function control. ST is a text language used for complex mathematical

12、 procedures and calculations less well suited to graphical languages. IL is a low-level language similar to assembly code. It is used in relatively simple logic instructions. Relay Ladder Logic (RLL), or ladder diagram